Help with custom note code.

Hey guys,

I found this cute code for adding a custom note to where I need in admin area. The problem with it is, that it gives out a php waning :

in_array() expects parameter 2 to be array, boolean given in…….

I can’t for life of me figure how to fix it.

add_action('admin_footer','print_mynote');
function print_mynote(){
    global $typenow,$pagenow;
    if  (in_array( $pagenow, array( 'post.php', 'post-new.php' )  && "Post_Type_Name" == $typenow )) {
        ?>
        <SCRIPT TYPE="text/javascript">
            jQuery(document).ready(function(){
                var myDiv = jQuery('<div>');
                myDiv.css("border","1px dashed #000000");
                myDiv.css("padding","5px");
                myDiv.css("background","lightyellow");
                myDiv.css("width","70%");
                myDiv.html("PUT your info help message here....");
                jQuery(".wrap").find("h2").after(myDiv);
            });
        </SCRIPT>
    <?php
    }
}

Any help would be appreciated ??